About Gravel

Size

• Gravel typically ranges between two millimeters and 63 millimeters in diameter. Those that fall in the one to four millimeter range are typically considered to be pebbles. Those pieces of rock that are smaller than gravel are called sane. Those that are larger than 63 millimeters in diameter are known as cobbles. A bunch of gravel that measures out to one square foot weighs about 100 pounds.

Function

• Gravel is used for a number of things, from lining the bottom of aquariums to building sculptures or other pieces of art. By far, though, gravel is most commonly used to top roadways. There are actually more roadways in the world that are completed with gravel on top than there are that use concrete or tarmac.

Geography

• Gravel is used all over the world, primarily in places where the roads are traveled fairly lightly. This is because it does not need as much upkeep as concrete or tarmac roads, and gravel makes a road cheaper to build. Russia, for example, has a staggering 400,000 kilometers of gravel roads running throughout the country. China also uses a great deal of gravel and is the world leader in the production of gravel.

Production

• Gravel naturally occurs in riverbeds or waterways because it is a product of the weathering away of larger rocks. Since gravel is not found everywhere naturally, people produce their own as well. This is done in gravel pits, where large boulders are crushed into smaller pieces to make up gravel. The rocks typically used in the man-made production of gravel are basalt, limestone or sandstone.

Types

• There are a number of different types of gravel that occur naturally. Bank gravel, for example, is gravel found mixed with clay or sand. Creek rock is gravel that has been polished by moving water and are smooth and rounded. Pea gravel is small and rounded. It is usually used in driveways. Other types of gravel include pay gravel, lag gravel and crushed rock gravel.